Insulating system for electric-transmission circuits.



No. 732,665 PATENTED JUNE 30, 1903..

A. w. UNDERWOOD. INSULATING SYSTEM FOR ELECTRIC TRANSMISSION CIRCUITS.

APPLICATION FILED DEG. 18, 1902..

UNITED STATES Patented June so, 1903.

PATENT OFFIC ALVAI-I IV. UNDERWOOD, OF PITTSFIELD, MASSACHUSETTS.

INSULATING SYSTEM FOR ELECTRIC-TRANSMISSION CIRCUITS.

SPECIFICATION forming part of Letters Patent N 0. 732,665, dated June 30, 1903.

Application filed December 18, 1902. Serial No. 135,763. (No model.)

T0 all whom it nutg concern;

Beitknown thatI,ALVAH W.UNDERWOOD, a citizen of the United States,residing atPittsfield, in the county ofBerkshire, State of Massachusetts, have invented certain new and useful Improvements in Insulating Systems for Electric-Transmission Circuits, of which the following is a specification, reference being had therein to the accompanying drawlugs.

This invention relates to an insulating system for electric-transmission circuits, and particularly to a structure wherein the insulator carrying a high-tension wire is carried by an insulated support.

The invention has for an object to provide an improved insulating-support carried at its opposite ends upon insulators and having these ends protected by caps, so that the water which may collect upon the support cannot pass to the cross-arm insulators.

A further object of the invention is to provide an improved form of these cross-arm insulators adapted to receive and retain the support in position, so that it can be readily assembled or removed whenever found necessary.

Other and further objects and advantages of the invention will be hereinafter set forth and the novel features of thesame defined by the appended claims.

In the drawings, Figure l is a side elevation of the invention; Fig. 2, an end view thereof;

Fig. 3, a vertical section on the line 3 3 of Fig. 1 with the insulator removed; Fig. 4, a

plan of the support for the main wire-insulator; Fig. 5, a side elevation thereof; Fig. 6, a vertical section of one of the supportinginsulators; Fig. 7, an elevation of a modified application of the invention, and Fig. 8 a further modification of the support.

Like letters of reference indicate like parts in the several figures of the drawings.

The letterA designates a cross-arm orsuitable supporting member of any desired character, which may extend laterally from a pole A or any suitable support. Upon this arm supporting-pins B are disposed and adapted to receive a skirted insulator B of any desired character, upon which a supporting-insulator B is secured in the usual manner, as shown in Fig. 6, and provided upon opposite be secured. formed of sheet metal, having a socket-B at sired character.

at opposite ends of the support 0 are similar .fnrcated arms 0 extend.

sides with lugs B disposed at a distance therefrom, so as to provide receiving-sockets for the ends of the support 0. Above these lugs a cap B of any desired character may For instance, this cap may be its center to fit over a perforated projection B upon the top of the supporting-insulator B and secured thereto bya pin 13 0f any do- The supporting-insulators in character.

The support or frame 0 may be of any desired material or configuration, but is preferably formed of plate material, as shown in Figs. 4 and 5, and provided with a central aperture 0, at each side of which the bi- The central portion 0 of this insulatoris disposed in a horizontal plane below the ends 0 and connected therewith by vertically-disposed portions 0 extending at an angle to the ends, so as to provide a support at the lowest possible point between the supporting-insulators, and thus secure the utmost rigidity and stability of the main insulator against lateral strain from high winds, while any moisture is drained away from the supports. This support 0, as before stated, may be of any desired matecoat the same with an insulating-covering G which is preferably formed of a suitable enamel, so as to prevent any conduction of an escaping current over the support. At opposite sides of the central opening 0 depending flanges O are provided, as shown in Figs. 3 and 5, while the bifurcated ends 0 are also provided with depending ends 0 to engage over the lugs B of the supporting-insulators, thus preventing movement of the support longitudinally thereof.

The main insulator D may be of any desired characterand is here shown as composed of a pin D, preferably of metal to prevent the burning out thereof by the leakage of a high-tension current, and upon this pin a skirted insulator D is secured, while disposed upon the latter is a supplemental insulator D carrying at its. upper end a cap D, having a water-conducting flange D extending about the edge thereof, while upon the upper face of this cap a socket D is provided to receive the high-tension wirev to be insulated, which maybe secured therein in any desired manner.

The supporting-pin D for the main insulator is adapted to pass through the aperture 0 in the support 0, and there is provided above this support a shoulder on the pin, between which and a contact-plate E a springwasher B is adapted to rest, while beneath the support a block E of any preferred material is disposed and provided with kerfs or grooves 11 therein to receive the flanges C from the support 0, and thus securely hold the parts against lateral movement upon the support. The lower end of the pin D is provided with a washer E and securing-nut E by means of which the several parts are clamped in position upon the support 0.

In Fig. 7 a modified application of the invention is shown in which the pins 13 of the supporting-insulators instead of being se cured to the cross-arm or support A are secured to a supplemental insulated support F, having two depending portions F and carried at its opposite ends F by means of supplemental supporting-insulators F similar in character to the supporting insulators hereinbefore described, and these insulators F are disposed upon a cross-arm or support A. The pins B are heldin position by clamping means F similar to thatdescribed in connection with the main insulator D and shown in Fig. 3, while the-support F is held between its ends by an additional insulator F similar to the insulators F This arrangement of the invention permits the carrying of additional wires, if so desired, and increases the insulation secured by the invention,which maybe desirable when the voltage of the current carried by the wire is unusually high.

It will be seen that the support 0 may be readily applied to the insulators B by engaging the ends thereof with the lugs upon the insulator and will be retained in position by the projections upon these ends, although the ends may be tied thereto in the usual manner if found desirable. By enameling this stamped metal-support with an insulating substance the conduction of leakage from the current through the support is effectually prevented, and the use of the caps upon the supporting-insulators prevents water passing over the ends of the support and down upon the insulators. A further important advantage is the disposition of the centralportion of the support in as low a plane as possible, so as to bring the center of gravity in such relation to the supports as to secure the maximum rigidity and stability of the main insulator. The clamping means for this main insulator effectually prevents any lateral movement thereof upon its support and forms a firm connection in which the plate above the support is adapted to conduct water beyond the sides thereof and prevent its contact with the support. The improved construction of the cap or rain-shield for the supporting-insulator and impair the surface supplied by the circuit.

In the modification shown in Fig. 8 the supporting-insulators are suspended from the cross-arm A by means of bolts G, having heads G in contact with the interior of the skirted insulator B, while the supportinginsulators are each protected at their top by an insulated rain-guard G In this arrangement of the invention the frame 0 is depressed more than is shown in Fig. 5, and should the wire D he accidentally displaced from its insulator it would contact with the insulated frame and be prevented from reaching the ground or the supporting-arm the same as in the other forms of the invention.

It will be apparent that the arrangement of these insulators may be altered, depending upon the existing conditions, and also that the configuration and details of construction thereof may be changed without departing from the spirit of the invention as defined by the appended claims.

Having described my invention and set forth its merits, what I claim, and desire to secure by Letters Patent, is-

1. In an electric-conductor support, supporting-insulators, a frame hearing at its opposite ends upon said insulators and having a depressed portion intermediate thereof, and a main insulator supported from the depressed portion of said frame; substantially as specified.

2. In an electric-conductor support, supporting-insulators, a frame hearing at its opposite ends upon said insulators, a main insulator supported from said frame, lugs upon said supporting-insulators spaced therefrom at opposite sides thereof, and open bifurcated ends to said frame to engage between the supporting-insulator and said lugs; substantially as specified.

3. In an electric-conductor support, supporting-insulators, a frame hearing at its opposite ends upon said insulators, a main insulator supported from said frame, lugs upon said supporting-insulators at opposite sides thereof, bifurcated ends to said frame adapted to contact with said lugs, and depending portions upon said ends to prevent lateral movement thereof; substantially as specified.

4. In an electric-conductor support, supporting-insulators, a frame hearing at its op posite ends upon said insulators, a main insulator suported from said frame,- lugs upon said supporting-insulators at opposite sides thereof, bifurcated ends to said frame adapt- IIO ed to contact with said lugs, depending portions upon said ends to prevent lateral movement thereof; and a cap or rain-guard above said ends; substantially as specified.

5. In an electric-conductor support, supporting-insulators, a frame hearing at its opposite ends upon said insulators, a main insulator supported from said frame, lugs upon said supporting-insulators at opposite sides thereof, bifurcated ends to said frame adapted to contact with said lugs, depending portions upon said ends to prevent lateral movement thereof, a cap or rain-guard above said ends, a pin for the main insulator extending through the supporting-frame, a plate above said frame, and a block beneath said frame adapted to engage a depending flange thereon; substantially as specified.

6. In. an electric-conductor support, supporting-insulators,a frame extendingbetween the same and supported at its opposite ends by resting thereon, removable caps supported by said insulators above said ends, said frame being removable by an upward movement after first removing the caps, and a main insulator carried by the frame between its ends; substantially as specified.

7. In an electric-conductor support, supporting-insulators,aframeextendingbetween the same and connected at its opposite ends thereto, a cap supported by said insulators above said ends, a central depressed portion in said frame extending in a parallel plane below the ends thereof, and a main insulator carried by said portion; substantially as specified.

8. In an electric-conductor support, supporting-insulators, a frame between the same having a central depressed apertured portion and bifurcated ends, depending flanges at opposite sides of the central portion, and a main insulator supported upon said portion; substantially as specified.

9. In an electric-conductor support, sup porting-insulators, a frame between the same having a central depressed apertured portion and bifurcated ends, depending flanges at opposite sides of the central portion, a maininsulator supported upon said portion, a pin carrying said main insulator and passing through said aperture, a plate disposed above said frame upon which said pin is adapted to rest, a block beneath said plate having grooves to receive the depending flanges of the frame, and means for clamping said parts to said frame; substantially as specified.

10. In an electric-conductor support, supporting-insnlators, a frame between the same having a centraldepressed apertured portion and bifurcated ends, depending flanges at opposite sides of the central portion, a main insulatorsupported upon said portion, a pin carrying said main insulator and passing through said aperture, a plate disposed above said frame upon which said pin is adapted to rest, a block beneath said plate having grooves to receive the depending flanges of the frame, means for clamping said parts to said frame, an insulating-coating to said frame, projecting lugs at opposite sides of the supportinginsulators, and depending ends upon said frame to engage said lugs and prevent longitudinal movement of the frame; substantially as specified.

11. In an electric-conductor support, a supporting-frame formed of sheet material having an insulating-coating thereon and provided with a central depressed apertured portion, depending flanges at opposite sides of said portion, and bifurcated ends at opposite sides of the central portion in a parallel plane above the same; substantially as specified.

12. In an electric-conductor support, a supporting-insulator having at its top an extended apertured projection, a metallic cap or rain-guard for said insulator provided with an apertured central socket fitted over said projection, and a securing means passing through said cap and projection; substantially as specified.

In testimony whereof I affix my signature in presence of two witnesses.

. ALVAII IV. UNDERVVOOD.v Witnesses:

F. W. GARRETT, HENRY L. DAWEs, Jr. 

